“…The existence of anti-periodic solutions to first order evolution problems has been considered by many mathematicians under several assumptions on nonlinear terms; we invite the readers to refer to [2], [12], [7], [8], [10], [9], [11], [23], [24] for further reading. Second order problems involving anti-periodic boundary conditions are considered in [1], [2], [3], [17], [18], [25], [26], [27].…”